B→Kη′decay as a unique probe of theη′meson

A theory of the $B\to K{\eta }^{\prime }$ decay is proposed. It is based on the Cabibbo-favored $b\to \overline{c}\mathrm{cs}$ process followed by a direct materialization of the $\overline{c}c$ pair into the ${\eta }^{\prime }.$ This mechanism works due to a nonvalence Zweig-rule-violating $c$-quark component of the ${\eta }^{\prime },$ which is unique to its very special nature. This nonperturbative “intrinsic charm” content of the ${\eta }^{\prime }$ is evaluated using the operator product expansion and QCD low-energy theorems. Our results are consistent with an unexpectedly large $B(B\to K{\eta }^{\prime })\simeq 7.8\times {10}^{-5}$ recently announced by CLEO.